Refactor database dialect types (#10437)

* Auto-commit work in progress before clean build on 2024-07-03 14:17:22 * Refactor * Revert * revert * Code Review feedback * Green * 2 Red * Green * Renames * Code review changes * Code review changes
enso-org · Jul 5, 2024 · fc93b4d · fc93b4d
1 parent 9449bf3
commit fc93b4d
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diff --git a/distribution/lib/Standard/AWS/0.0.0-dev/src/Database/Redshift/Internal/Redshift_Dialect.enso b/distribution/lib/Standard/AWS/0.0.0-dev/src/Database/Redshift/Internal/Redshift_Dialect.enso
@@ -22,6 +22,7 @@ import Standard.Database.Internal.Postgres.Postgres_Type_Mapping.Postgres_Type_M
 import Standard.Database.Internal.SQL_Type_Mapping.SQL_Type_Mapping
 import Standard.Database.Internal.SQL_Type_Reference.SQL_Type_Reference
 import Standard.Database.Internal.Statement_Setter.Statement_Setter
+import Standard.Database.SQL.SQL_Builder
 import Standard.Database.SQL_Statement.SQL_Statement
 import Standard.Database.SQL_Type.SQL_Type
 from Standard.Database.Errors import SQL_Error, Unsupported_Database_Operation
@@ -33,7 +34,7 @@ import project.Database.Redshift.Internal.Redshift_Error_Mapper.Redshift_Error_M
    The dialect for Redshift connections.
 redshift : Redshift_Dialect
 redshift =
-    Redshift_Dialect.Value Postgres_Dialect.make_internal_generator_dialect
+    Redshift_Dialect.Value Postgres_Dialect.make_dialect_operations
 
 ## PRIVATE
 
@@ -42,7 +43,7 @@ type Redshift_Dialect
     ## PRIVATE
 
        The dialect for Redshift connections.
-    Value internal_generator_dialect
+    Value dialect_operations
 
     ## PRIVATE
        Name of the dialect.
@@ -57,15 +58,28 @@ type Redshift_Dialect
        according to the specific dialect.
     generate_sql : Query -> SQL_Statement
     generate_sql self query =
-        Base_Generator.generate_query self.internal_generator_dialect query . build
+        Base_Generator.generate_query self query . build
+
+    ## PRIVATE
+       Generates SQL to truncate a table.
+    generate_truncate_table_sql : Text -> SQL_Builder
+    generate_truncate_table_sql self table_name =
+        Base_Generator.truncate_table_delete_from_style self table_name
 
     ## PRIVATE
        Wraps and possibly escapes the identifier so that it can be used in a
        generated query regardless of what characters it contains.
        The quotes used will depend on the dialect.
-    wrap_identifier : Text -> Text
+    wrap_identifier : Text -> SQL_Builder
     wrap_identifier self identifier =
-        self.internal_generator_dialect.wrap_identifier_raw identifier
+        Base_Generator.wrap_in_quotes identifier
+
+   ## PRIVATE
+      Generates a SQL expression for a table literal.
+   make_table_literal : Vector (Vector Text) -> Vector Text -> Text -> SQL_Builder
+   make_table_literal self vecs column_names as_name =
+       Base_Generator.default_make_table_literal self.wrap_identifier vecs column_names as_name
+
 
     ## PRIVATE
        Prepares an ordering descriptor.
@@ -159,7 +173,7 @@ type Redshift_Dialect
        Checks if an operation is supported by the dialect.
     is_supported : Text -> Boolean
     is_supported self operation =
-        self.internal_generator_dialect.is_supported operation
+        self.dialect_operations.is_supported operation
 
     ## PRIVATE
        The default table types to use when listing tables.

diff --git a/distribution/lib/Standard/Database/0.0.0-dev/src/Dialect.enso b/distribution/lib/Standard/Database/0.0.0-dev/src/Dialect.enso
@@ -21,6 +21,7 @@ import project.Internal.SQL_Type_Mapping.SQL_Type_Mapping
 import project.Internal.SQL_Type_Reference.SQL_Type_Reference
 import project.Internal.SQLite.SQLite_Dialect
 import project.Internal.Statement_Setter.Statement_Setter
+import project.SQL.SQL_Builder
 import project.SQL_Statement.SQL_Statement
 import project.SQL_Type.SQL_Type
 from project.Errors import SQL_Error, Unsupported_Database_Operation
@@ -46,6 +47,13 @@ type Dialect
         _ = [query]
         Unimplemented.throw "This is an interface only."
 
+    ## PRIVATE
+       Generates SQL to truncate a table.
+    generate_truncate_table_sql : Text -> SQL_Builder
+    generate_truncate_table_sql self table_name =
+         _ = [table_name]
+         Unimplemented.throw "This is an interface only."
+
     ## PRIVATE
        Prepares an ordering descriptor.
 

diff --git a/distribution/lib/Standard/Database/0.0.0-dev/src/Internal/Base_Generator.enso b/distribution/lib/Standard/Database/0.0.0-dev/src/Internal/Base_Generator.enso
@@ -2,6 +2,7 @@ from Standard.Base import all
 import Standard.Base.Errors.Illegal_State.Illegal_State
 
 import project.Column_Constraint.Column_Constraint
+import project.Dialect.Dialect
 import project.Internal.IR.Context.Context
 import project.Internal.IR.From_Spec.From_Spec
 import project.Internal.IR.Nulls_Order.Nulls_Order
@@ -13,52 +14,37 @@ import project.SQL.SQL_Builder
 from project.Errors import Unsupported_Database_Operation
 from project.Internal.IR.Operation_Metadata import Row_Number_Metadata
 
-type Internal_Dialect
+type Dialect_Operations
 
     ## PRIVATE
 
-       An internal representation of a SQL dialect.
+       Operations supported by a particular SQL dialect and how they are implemeneted.
 
        Arguments:
        - operation_map: The mapping which maps operation names to their
          implementations; each implementation is a function which takes SQL
          builders for the arguments, and optionally an additional metadata
          argument, and should return a SQL builder yielding code for the whole
          operation.
-       - wrap_identifier_raw: A function that converts an arbitrary supported
-         identifier name in such a way that it can be used in the query; that
-         usually consists of wrapping the name in quotes and escaping any quotes
-         within it.
-       - make_table_literal: A function that generates a SQL expression for a
-         table literal.
-    Value (operation_map:(Map Text (Vector (SQL_Builder->SQL_Builder)))) (wrap_identifier_raw:(Text->Text)) (make_table_literal : Vector (Vector Text) -> Vector Text -> Text -> SQL_Builder)
-
-    ## PRIVATE
-    wrap_identifier : Text -> SQL_Builder
-    wrap_identifier self identifier:Text =
-        SQL_Builder.code (self.wrap_identifier_raw identifier)
+    Value (operation_map:(Map Text (Vector (SQL_Builder->SQL_Builder))))
 
     ## PRIVATE
 
        Creates a copy of the dialect that supports additional operations or
        overrides existing ones.
 
-       # extend_with : Vector [Text, Vector SQL_Builder -> SQL_Builder] -> Internal_Dialect
-    extend_with : Vector Any -> Internal_Dialect
+       # extend_with : Vector [Text, Vector SQL_Builder -> SQL_Builder] -> Dialect_Operations
+    extend_with : Vector Any -> Dialect_Operations
     extend_with self mappings =
         new_map = mappings.fold self.operation_map (m -> el -> m.insert (el.at 0) (el.at 1))
-        Internal_Dialect.Value new_map self.wrap_identifier_raw self.make_table_literal
+        Dialect_Operations.Value new_map
 
     ## PRIVATE
        Checks if an operation is supported by the dialect.
     is_supported : Text -> Boolean
     is_supported self operation =
         self.operation_map.contains_key operation
 
-    ## PRIVATE
-    override_make_table_literal self (make_table_literal : Vector (Vector Text) -> Vector Text -> Text -> SQL_Builder) -> Internal_Dialect =
-        Internal_Dialect.Value self.operation_map self.wrap_identifier_raw make_table_literal
-
 ## PRIVATE
 
    A helper function to create a binary operator.
@@ -185,18 +171,18 @@ make_constant sql_code =
 
    This is the simplest way of escaping identifiers that should work across most
    dialects.
-wrap_in_quotes : Text -> Text
+wrap_in_quotes : Text -> SQL_Builder
 wrap_in_quotes identifier =
     escaped = identifier.replace '"' '""'
-    '"'+escaped+'"'
+    SQL_Builder.code ('"'+escaped+'"')
 
 ## PRIVATE
 
    The base SQL dialect that is shared between most SQL implementations.
 
    It is a base to help creating concrete dialects. It can be extended or
    completely overridden.
-base_dialect =
+base_dialect_operations =
     bin = name -> [name, make_binary_op name]
     unary = name -> [name, make_unary_op name]
     fun = name -> [name, make_function name]
@@ -215,7 +201,7 @@ base_dialect =
     types = [simple_cast]
     windows = [["ROW_NUMBER", make_row_number], ["ROW_NUMBER_IN_GROUP", make_row_number_in_group]]
     base_map = Map.from_vector (arith + logic + compare + functions + agg + counts + text + nulls + contains + types + windows)
-    Internal_Dialect.Value base_map wrap_in_quotes (default_make_table_literal wrap_in_quotes)
+    Dialect_Operations.Value base_map
 
 ## PRIVATE
 is_empty = lift_unary_op "IS_EMPTY" arg->
@@ -315,7 +301,7 @@ make_row_number_in_group arguments =
    Arguments:
    - dialect: The SQL dialect in which the expression is being generated.
    - expr: The expression to generate SQL code for.
-generate_expression : Internal_Dialect -> SQL_Expression | Order_Descriptor | Query -> SQL_Builder
+generate_expression : Dialect -> SQL_Expression | Order_Descriptor | Query -> SQL_Builder
 generate_expression dialect expr = case expr of
     SQL_Expression.Column origin name ->
         dialect.wrap_identifier origin ++ '.' ++ dialect.wrap_identifier name
@@ -325,7 +311,7 @@ generate_expression dialect expr = case expr of
         escaped = value.replace "'" "''"
         SQL_Builder.code ("'" + escaped + "'")
     SQL_Expression.Operation kind arguments metadata ->
-        op = dialect.operation_map.get kind (Error.throw <| Unsupported_Database_Operation.Error kind)
+        op = dialect.dialect_operations.operation_map.get kind (Error.throw <| Unsupported_Database_Operation.Error kind)
         parsed_args = arguments.map (generate_expression dialect)
         result = op parsed_args
         # If the function expects more arguments, we pass the metadata as the last argument.
@@ -343,7 +329,7 @@ generate_expression dialect expr = case expr of
    Arguments:
    - dialect: The dialect for which to add the alias.
    - name: The name of the alias.
-alias : Internal_Dialect -> Text -> SQL_Builder
+alias : Dialect -> Text -> SQL_Builder
 alias dialect name =
     wrapped = dialect.wrap_identifier name
     SQL_Builder.code " AS " ++ wrapped
@@ -355,7 +341,7 @@ alias dialect name =
    Arguments:
    - dialect: The SQL dialect for which the code is generated.
    - from_spec: A description of the FROM clause.
-generate_from_part : Internal_Dialect -> From_Spec -> SQL_Builder
+generate_from_part : Dialect -> From_Spec -> SQL_Builder
 generate_from_part dialect from_spec = case from_spec of
     From_Spec.Table name as_name _ ->
         dialect.wrap_identifier name ++ alias dialect as_name
@@ -384,9 +370,7 @@ generate_from_part dialect from_spec = case from_spec of
 ## PRIVATE
 default_make_table_literal wrap_identifier vecs column_names as_name =
     values = SQL_Builder.join ", " (vecs.transpose.map (vec-> SQL_Builder.join ", " (vec.map SQL_Builder.interpolation) . paren))
-    wrap_identifier_as_builder n =
-        SQL_Builder.code (wrap_identifier n)
-    structure = (wrap_identifier_as_builder as_name) ++ (SQL_Builder.join ", " (column_names.map wrap_identifier_as_builder) . paren)
+    structure = (wrap_identifier as_name) ++ (SQL_Builder.join ", " (column_names.map wrap_identifier) . paren)
     SQL_Builder.code "(VALUES " ++ values ++ ") AS " ++ structure
 
 ## PRIVATE
@@ -420,7 +404,7 @@ make_not_equals a b =
    Arguments:
    - dialect: The SQL dialect for which the code is generated.
    - order_descriptor: A description of the ORDER clause.
-generate_order : Internal_Dialect -> Order_Descriptor -> SQL_Builder
+generate_order : Dialect -> Order_Descriptor -> SQL_Builder
 generate_order dialect order_descriptor =
     order_suffix = case order_descriptor.direction of
         Sort_Direction.Ascending -> " ASC"
@@ -443,7 +427,7 @@ generate_order dialect order_descriptor =
    Arguments:
    - dialect: The SQL dialect for which the code is being generated.
    - ctx: A description of the SELECT clause.
-generate_select_context : Internal_Dialect -> Context -> SQL_Builder
+generate_select_context : Dialect -> Context -> SQL_Builder
 generate_select_context dialect ctx =
     gen_exprs exprs = exprs.map (generate_expression dialect)
     from_part = generate_from_part dialect ctx.from_spec
@@ -466,7 +450,7 @@ generate_select_context dialect ctx =
    - table_name: The name of the table into which the values are being inserted.
    - pairs: The values to insert into the table, consisting of pairs of key, and
      expression returning a value.
-generate_insert_query : Internal_Dialect -> Text -> Vector Any -> SQL_Builder
+generate_insert_query : Dialect -> Text -> Vector Any -> SQL_Builder
 generate_insert_query dialect table_name pairs =
     names = SQL_Builder.join ", " <| pairs.map (.first >> dialect.wrap_identifier)
     values = SQL_Builder.join ", " <| pairs.map (.second >> generate_expression dialect)
@@ -481,7 +465,7 @@ generate_insert_query dialect table_name pairs =
    Arguments:
    - dialect: The SQL dialect for which the code is being generated.
    - query: An IR describing the query.
-generate_query : Internal_Dialect -> Query -> SQL_Builder
+generate_query : Dialect -> Query -> SQL_Builder
 generate_query dialect query = case query of
     Query.Select columns ctx ->
         gen_column pair = (generate_expression dialect pair.second) ++ alias dialect pair.first
@@ -504,7 +488,7 @@ generate_query dialect query = case query of
         maybe_if_exists = if if_exists then SQL_Builder.code "IF EXISTS " else SQL_Builder.empty
         SQL_Builder.code "DROP TABLE " ++ maybe_if_exists ++ dialect.wrap_identifier name
     Query.Truncate_Table name ->
-        SQL_Builder.code "DELETE FROM " ++ dialect.wrap_identifier name
+        dialect.generate_truncate_table_sql name
     Query.Insert_From_Select table_name column_names select_query -> case select_query of
         Query.Select _ _ ->
             inner_query = generate_query dialect select_query
@@ -617,3 +601,15 @@ generate_column_description dialect descriptor =
    like a SQL query for the given dialect or is rather a table name.
 is_probably_a_query : Text -> Boolean
 is_probably_a_query text = (text.contains "SELECT ") || (text.contains "EXEC ")
+
+## PRIVATE
+   option for implementing generate_truncate_table_sql
+truncate_table_delete_from_style : Dialect -> Text -> SQL_Builder
+truncate_table_delete_from_style dialect table_name =
+    SQL_Builder.code "DELETE FROM " ++ dialect.wrap_identifier table_name
+
+## PRIVATE
+   option for implementing generate_truncate_table_sql
+truncate_table_truncate_table_style : Dialect -> Text -> SQL_Builder
+truncate_table_truncate_table_style dialect table_name =
+    SQL_Builder.code "TRUNCATE TABLE " ++ dialect.wrap_identifier table_name
diff --git a/distribution/lib/Standard/Database/0.0.0-dev/src/Internal/Postgres/Postgres_Dialect.enso b/distribution/lib/Standard/Database/0.0.0-dev/src/Internal/Postgres/Postgres_Dialect.enso
@@ -46,14 +46,14 @@ polyglot java import java.sql.Types
    The dialect of PostgreSQL databases.
 postgres : Postgres_Dialect
 postgres =
-    Postgres_Dialect.Value make_internal_generator_dialect
+    Postgres_Dialect.Value make_dialect_operations
 
 ## PRIVATE
    The dialect of PostgreSQL databases.
 type Postgres_Dialect
     ## PRIVATE
        The dialect of PostgreSQL databases.
-    Value internal_generator_dialect
+    Value dialect_operations
 
     ## PRIVATE
        Name of the dialect.
@@ -69,23 +69,27 @@ type Postgres_Dialect
        according to the specific dialect.
     generate_sql : Query -> SQL_Statement
     generate_sql self query =
-        case query of
-            # Special handling to use TRUNCATE TABLE instead of the default (since being more portable) DELETE FROM.
-            Query.Truncate_Table name ->
-                wrapped_name = self.internal_generator_dialect.wrap_identifier name
-                # ONLY is used to avoid truncating other tables that inherit from this table, which is the default behaviour on Postgres.
-                (SQL_Builder.code "TRUNCATE TABLE ONLY " ++ wrapped_name) . build
-            _ ->
-                # Rely on the base generator for most queries.
-                Base_Generator.generate_query self.internal_generator_dialect query . build
+        Base_Generator.generate_query self query . build
+
+    ## PRIVATE
+       Generates SQL to truncate a table.
+    generate_truncate_table_sql : Text -> SQL_Builder
+    generate_truncate_table_sql self table_name =
+        Base_Generator.truncate_table_truncate_table_style self table_name
 
     ## PRIVATE
        Wraps and possibly escapes the identifier so that it can be used in a
        generated query regardless of what characters it contains.
        The quotes used will depend on the dialect.
-    wrap_identifier : Text -> Text
+    wrap_identifier : Text -> SQL_Builder
     wrap_identifier self identifier =
-        self.internal_generator_dialect.wrap_identifier_raw identifier
+        Base_Generator.wrap_in_quotes identifier
+
+   ## PRIVATE
+      Generates a SQL expression for a table literal.
+   make_table_literal : Vector (Vector Text) -> Vector Text -> Text -> SQL_Builder
+   make_table_literal self vecs column_names as_name =
+       Base_Generator.default_make_table_literal self.wrap_identifier vecs column_names as_name
 
     ## PRIVATE
        Prepares an ordering descriptor.
@@ -242,7 +246,7 @@ type Postgres_Dialect
        Checks if an operation is supported by the dialect.
     is_supported : Text -> Boolean
     is_supported self operation =
-        self.internal_generator_dialect.is_supported operation
+        self.dialect_operations.is_supported operation
 
     ## PRIVATE
        The default table types to use when listing tables.
@@ -299,7 +303,7 @@ type Postgres_Dialect
                 _ -> base_type
 
 ## PRIVATE
-make_internal_generator_dialect =
+make_dialect_operations =
     cases = [["LOWER", Base_Generator.make_function "LOWER"], ["UPPER", Base_Generator.make_function "UPPER"]]
     text = [starts_with, contains, ends_with, agg_shortest, agg_longest, make_case_sensitive, ["REPLACE", replace], left, right]+concat_ops+cases+trim_ops
     counts = [agg_count_is_null, agg_count_empty, agg_count_not_empty, ["COUNT_DISTINCT", agg_count_distinct], ["COUNT_DISTINCT_INCLUDE_NULL", agg_count_distinct_include_null]]
@@ -313,7 +317,7 @@ make_internal_generator_dialect =
     special_overrides = [is_null, is_empty]
     other = [["RUNTIME_ERROR", make_runtime_error_op]]
     my_mappings = text + counts + stats + first_last_aggregators + arith_extensions + bool + date_ops + special_overrides + other
-    Base_Generator.base_dialect . extend_with my_mappings
+    Base_Generator.base_dialect_operations . extend_with my_mappings
 
 ## PRIVATE
    This overrides the default behaviour, due to a weird behaviour of Postgres -